1. Field of the Invention
The present invention relates to an apparatus and method for highly accurate real-time photoelectric glass substrate identification, and more particularly, relates to an apparatus and method utilizing a digital signal processing (DSP) method to facilitate highly accurate real-time photoelectric glass substrate identification.
2. Description of Related Art
In industries such as the liquid crystal device (LCD), plasma display panel (PDP), organic light emitting diode (OLED), digital camera or smart phone industries in which display devices are applicable, glass material is commonly used as the substrate of various displays, and each glass material is widely applied in the manufacturing processes in a form of thin substrate. In addition, in areas of the pick-up head prism such as the bonding of silicon chips, micro electro mechanical systems (MEMS), MEMS of fiber optics device, biopharmaceutical areas, micro mirror, polarized beam splitter, substrates of dichroic filter, micro glass-block and lens, DVD and continuous data protection (CDP), a variety of glass substrates are also used.
Furthermore, in high-tech industries such as the semiconductor manufacturing equipment industry, precision machinery industry and display devices industry mentioned above, it is a trend to design products in nano-level with miniaturization and precision. Therefore, in the development process of manufacturing techniques, integration techniques and measuring equipment of the precision machinery area, inspecting techniques of the glass substrate thickness have become rather important.
In order to meet the measuring requirements of the precision machinery area, one of the conventional inspecting techniques utilizes the wavelength of lights to obtain the glass substrate thickness. However, in such a conventional technique of using the wavelength to measure glass thickness, not only is the set up difficult, but the cost of the precision equipment is also too high. Therefore, such a technique still has rooms for improvements.
On the other hand, because of the characteristics of high strength and high directionality of the laser beam, laser devices have also been used by some conventional techniques to measure glass thickness. However, such techniques often require multiple sets of laser light source, multiple sets of glass substrates and multiple sets of charged coupled device (CCD) camera inspecting equipment to perform the measurement. Hence, such techniques are disadvantageous in its high cost and its incapability to perform real-time inspection.
Therefore, there is an urgent need for the industry to develop an apparatus with a simplified structure that uses laser to inspect the thickness of glass substrates and a method thereof. It is preferable for such an apparatus and method to be able to lower the cost of the inspection equipment, increase the speed of the inspection process while performing real-time inspection.